Bat and ball sports of the foregoing kind generally involve a contest between the batter and the ball deliverer, with the general object of the ball deliverer being to deliver the ball in such a manner that the batter misses or mishits the ball. One method used to frustrate the batter is to curve or swing the ball during flight from the ball deliverer to the batter. An experienced baseball pitcher can make a baseball curve towards or away from a batter provided the ball is pitched, with sufficient speed and horizontal rotation. For example, a ball pitched at 115 kilometers per hour rotating horizontally at 1800 rpm should move about 0.5 meters from a straight path between the pitcher's mound and the batting plate. Similarly, an experienced cricket bowler bowling a ball between 105 and 120 kilometers per hour with its seam angle between 15° to 40° to the direction of travel having the shinier of the two halves of the cricket ball presenting a leading face, while rotating about its seam, will swing towards the rougher side. Quite naturally, combining these requirements with the general requirement of pitching the ball to pass over the batting plate, or bowling the ball at the cricket stumps, is beyond the average player.
Whilst the specifications of a baseball/cricket ball are set according to the rules of the sport, there are situations, such as in practice or a social game, where a strict adherence is not mandatory. It would be advantageous in these situations to provide a ball Which facilitated a pitcher/bowler to curve/swing the ball.